In conjunction with many devices there is a need to monitor the condition of joints between different elements of a device. For example, the device may comprise a circuit board, an electronic component, such as e.g. an integrated circuit, on the surface of the circuit board, and a cooling element that is pressed against the electronic component so that the electronic component is between the circuit board and the cooling element. A typical mechanical structure for pressing the cooling element against the electronic component comprises bolts or other threaded rods and nuts attached to the circuit board so that the required pressing force is generated by tightening the bolts or other threaded rod to the nuts. The integration level of modern electrical devices is often so high that it is not possible to provide the circuit board with through holes for the above-mentioned bolts. Therefore, in many cases, the above-mentioned nuts are surface mounted devices “SMD” in order to avoid the need for holes through the circuit board. However, the joint between the circuit board and the SMD-nut should be very reliable or at least its condition should be monitored because loosening of the joint leads to a situation in which the thermal conductivity of the contact between the electronic component and the cooling element decreases and, as a corollary, the cooling is weakened and the electronic component may be overheated and finally destroyed. Thus, it is important to get an alarm already at an early stage when a fault in the joint between the SMD-nut and the circuit board is evolving. Another example, where condition monitoring of a joint between elements is applicable, is indication of unauthorized opening of a casing of a device. The indication may be used, for example, as a proof that a warranty is void.